Replacing piston on 1g???

[1997RS]

Can I purchase one Piston and replace my stock gsx or would you guys suggest replacing all at once???

George

 

[AWDlaserRS]

Whats wrong with the car? How do you know you have to replace a piston?

 

[1997RS]

well piston #1 on top of the exhaust side is not entirely rounded kinda oval shaped just on the exhaust side so i was wondering since the cylinder wall looks good if i could just change the one piston or rebuild the whole thing what do you think i should do???